New developments in melanoma: utility of ultrasound imaging (initial staging,follow-up and pre-SLNB)

Melanoma incidence is still increasing, but the mortality rate has remained unchanged. Lymph node metastases are the single most important prognostic factor for stage I/II melanoma patients. Currently, the standard of care with regard to the staging of these patients is the surgical sentinel node procedure. Ultrasound is not routine for the diagnostic work-up of primary melanomas. Some may use ultrasound for the preoperative assessment of the tumor thickness and lymphatic drainage, but this has not found wide application. For the follow-up of melanoma patients, ultrasound has been proven to be superior to physical examination for the detection of lymph node metastases. A meta-analysis has shown that ultrasound is superior to computed tomography (CT) and/or positron emission tomography (PET)-CT for the detection of lymph node metastases, whereas PET-CT was superior for the detection of distant visceral metastases. Ultrasound of regional lymph nodes has been incorporated into many national guidelines across Europe and in Australia for the follow-up of melanoma patients. A new avenue for ultrasound (US)-guided fine-needle aspiration cytology (FNAC) is the pre-sentinel node modality. Like the situation in breast and thyroid cancer, US-FNAC, a minimally invasive procedure, may decrease the need for surgical sentinel node staging. New ultrasound morphology criteria have significantly increased the sensitivity of this technique. Peripheral perfusion is an early sign of metastases (77% sensitivity, 52% positive-predictive value), whereas balloon-shaped lymph node was a late sign of metastases (30% sensitivity, 96% positive-predictive value). Together, these new ultrasound morphology criteria were able to accurately demonstrate metastases in 65% of sentinel node-positive patients. Future perspectives of ultrasound in melanoma include the start of a large multicenter, multicountry validation study – USE-FNAC – by the European Organisation for Research and Treatment of Cancer (EORTC) Melanoma Group. In light of new and promising adjuvant therapies, the need for ultrasound staging might increase rapidly.     

The utility of initial staging PET-CT as a baseline scan for surveillance imaging in stage II and III melanoma

BackgroundThis study evaluates the utility of whole-body PET-CT for the initial staging and subsequent surveillance imaging of patients with completely resected stage II and stage III melanoma.MethodsA single-center, retrospective review of patients who received perioperative whole-body PET-CT from January 1, 2005 to December 1, 2019 within three months of initial melanoma diagnosis was performed.ResultsOf 258 total patients with completely resected melanoma who had a PET-CT within 3 months after their melanoma diagnosis, 113 had stage II and 145 had stage III melanoma. PET-CT detected distant metastasis in 3 (2.7%) of 113 stage II patients and 7 (4.8%) of 145 stage III patients.179 of 258 patients had adequate follow-up time to determine whether they received surveillance cross-sectional imaging and whether they had a melanoma recurrence. 143 (79.9%) received subsequent surveillance imaging, 74 of whom developed a recurrence. In 64 (86.5%) of 74 cases, recurrence was detected by routine surveillance. 26 (34.2%) of 76 stage II and 65 (63.1%) of 103 stage III patients developed a recurrence. The median time to recurrence among the 179 patients for stage II and III was 16.3 and 13.0 months, respectively.ConclusionsThese findings indicate that baseline staging with whole-body PET-CT rarely provides information that changes initial management. Rather, the value of the initial PET-CT is as a baseline for subsequent surveillance scans. Therefore, it may be premature to discourage cross-sectional imaging for patients with stage II and III melanoma without supportive evidence or a reliable biomarker of recurrent disease.     

The utility of ultrasound in patients with melanoma

The highest quality gray-scale ultrasound images are obtained with high-frequency transducers; however, such high frequencies do not penetrate more than a few centimeters into body tissue. Fortunately, in patients with melanoma, the structures of interest are close to the skin surface, making them ideal targets for examination with high-resolution ultrasound. These include primary cutaneous melanomas, uveal melanomas and the regional lymph nodes draining the skin that lie in the axilla, groin, neck and other locations. Although ultrasound study of primary melanomas arising in the skin and eye has provided some insights, a major role for ultrasound has evolved recently, to provide early detection of metastatic melanoma in regional lymph nodes. Ultrasound is clearly superior to clinical palpation of the nodes during follow-up and, when combined with guided fine-needle biopsy, allows the earliest possible surgical intervention for regional nodal metastases. In the future the use of ultrasound contrast agents may improve the sensitivity of ultrasound in the detection of very small metastatic deposits.     

The utility of ultrasound in patients with melanoma

The highest quality gray-scale ultrasound images are obtained with high-frequency transducers; however, such high frequencies do not penetrate more than a few centimeters into body tissue. Fortunately, in patients with melanoma, the structures of interest are close to the skin surface, making them ideal targets for examination with high-resolution ultrasound. These include primary cutaneous melanomas, uveal melanomas and the regional lymph nodes draining the skin that lie in the axilla, groin, neck and other locations. Although ultrasound study of primary melanomas arising in the skin and eye has provided some insights, a major role for ultrasound has evolved recently, to provide early detection of metastatic melanoma in regional lymph nodes. Ultrasound is clearly superior to clinical palpation of the nodes during follow-up and, when combined with guided fine-needle biopsy, allows the earliest possible surgical intervention for regional nodal metastases. In the future the use of ultrasound contrast agents may improve the sensitivity of ultrasound in the detection of very small metastatic deposits.     

The utility of magnetic resonance imaging in the detection of brain metastases in the staging of cutaneous melanoma

AimsTo retrospectively evaluate the use of brain magnetic resonance imaging (MRI) in the initial staging of patients with cutaneous melanoma in our melanoma unit.Materials and methodsThe radiology request forms for brain MRI for melanoma staging for 193 consecutive patients were reviewed. Patient hospital records were also retrospectively reviewed. Patients with no histological confirmation of a cutaneous primary or patients whose scan was to primarily investigate their neurological symptoms were excluded. Records were also searched for incidental symptoms that may have been associated with brain metastases.ResultsOne hundred patients were eligible. No patients were upstaged by MRI. Of a total of 33 patients already graded as stage IV by prior staging, 11 (33%) were found to have brain metastases. No patients graded less than stage IV were found to have brain metastases on MRI. Six out of 12 patients with incidental symptoms had metastases. Five patients graded as stage IV had asymptomatic brain metastases.ConclusionWe recommend brain MRI only for patients with stage IV disease and for other patients with melanoma contemplating further adjuvant therapy where brain metastases would change management.     

Noninvasive imaging for staging of prostate cancer: magnetic resonance imaging, computed tomography, and ultrasound

The diagnosis of prostate carcinoma by imaging is still fraught with problems, even with the advent of highly sophisticated techniques. Despite enthusiastic preliminary reports, no one imaging method reliably screens for this condition. The staging of prostate carcinoma is feasible, but the best imaging method remains a subject of debate. The transabdominal sonographic approach lacks the resolution required for detailed intraglandular anatomic delineation. The transrectal sonographic approach excels in guiding needle biopsy and in evaluating transcapsular and seminal vesicle extension of known tumors. Computed tomography lags behind other tomographic imaging modalities in its accuracy for local tumor staging, but it is excellent, although nonspecific, in the detection of lymph node enlargement. Magnetic resonance detects abnormalities in the prostate in a high percentage of cases but is nonspecific. However, it can stage prostate carcinoma and detect lymphadenopathy reliably.     

Primary staging and follow-up in melanoma patients--monocenter evaluation of methods,costs and patient survival

In a German cohort of 661 melanoma patients the performance, costs and survival benefits of staging methods (history and physical examination; chest X-ray; ultrasonography of the abdomen; high resolution sonography of the peripheral lymph nodes) were assessed at initial staging and during follow-up of stage I/II+III disease. At initial staging, 74% (23 out of 31) of synchronous metastases were first detected by physical examination followed by sonography of the lymph nodes revealing 16% (5 out of 31). Other imaging methods were less efficient (Chest X-ray: one out of 31; sonography of abdomen: two out of 31). Nearly 24% of all 127 first recurrences and 18% of 73 second recurrences developed in patients not participating in the follow-up programme. In follow-up patients detection of first or second recurrence were attributed to history and physical examination on a routine visit in 47 and 52% recurrences, respectively, and to routine imaging procedures in 21 and 17% of cases, respectively. Lymph node sonography was the most successful technical staging procedure indicating 13% of first relapses, but comprised 24% of total costs of follow-up in stage I/II. Routine imaging comprised nearly 50% of total costs for follow-up in stage I/II and in stage III. The mode of detecting a relapse ('patient vs. doctor-diagnosed' or 'symptomatic vs asymptomatic') did not significantly influence patients overall survival. Taken together, imaging procedures for routine follow-up in stage I/II and stage III melanoma patients were inefficient and not cost-efficient.     

Modern staging and utility of PET imaging in esophageal cancer management

Esophageal cancer is the eighth most common cancer worldwide, and one of the most fatal diseases despite modern medical treatment. Because correct staging and surveillance of neoadjuvant therapy for esophageal cancer is mandatory for further treatment planning, choosing a modern imaging system is important. The development of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has provided alternate means of tumor detection distinct from more conventional methods. This modality has extraordinary performance in detecting locoregional lymph node involvement and distant metastatic disease, and has been introduced as a powerful tool in many guidelines. However, some factors still lead to false-negative or -positive results, raising questions of its accuracy. This article discusses the clinical efficacy of PET in staging and surveillance of neoadjuvant therapy in esophageal cancer, comparing its accuracy with conventional imaging modalities.     

High frequency ultrasound in the preoperative staging of primary melanoma: a statistical analysis

High frequency sonography has been shown to be a useful tool in the preoperative staging of malignant melanoma. In the present study sonometric and histometric data concerning tumour thickness were compared, using appropriate statistical methods, in order to assess the accuracy of ultrasonography. From December 1997 all pigmented lesions suspected of being melanoma were preoperatively assessed by a 20 MHz ultrasound B scan. The results of these ultrasound examinations were compared with histometric data. Pearson's correlation coefficient and absolute and relative differences were used for statistical analysis. Of the 261 examined lesions, 193 were malignant melanoma. A high correlation between sonometry and histometry was computed (r = 0.95), with an absolute difference of 0.32 +/- 0.03 mm (mean +/- SEM) and a mean relative difference of 27.2% (95% confidence interval 23-31.4%). The highest correlation was found in melanoma > or = 1.51 mm thick and the lowest correlation in melanoma < or = 0.75 mm. In conclusion, the high accuracy of this technique in the preoperative staging of malignant melanoma would offer a basis for defining the surgical margins of > or = 0.76 mm thick lesions. The limited accuracy of sonometry in the preoperative staging of thin melanoma < or = 0.75 mm has emerged by applying adequate statistical methods.     

New developments in breast imaging]

In 2004, breast cancer screening will be effective in France. This evolution has a strong impact on our mammographic practice that becomes a real mission of public health. Digital mammography, compared to screen-film mammography, provides the same results for the detection of breast cancer, computer-aided detection systems represent the most relevant application of this technology at this time. The setting up of a quality control will allow the introduction of this technology in screening during 2004. Percutaneous imaging-guided procedures are now currently used for the diagnosis of nonpalpable breast lesions and allow the selection of patients for surgery. These procedures have emphasized the need for a multidisciplinary approach of the patients. Indications of MRI have not changed because of its moderated specificity and no relevant development of interventional-guided procedures. Work on standardization of radiological reports and assessment categories goes on. This classification is already applied for mammography, and new classifications for lesions detected by ultrasound or MRI will be published by the American College of Radiology (Breast Imaging Reporting and Data System, 4th edition, available in 2003).     

Preoperative staging of liver metastases from uveal melanoma by magnetic resonance imaging (MRI) and fluorodeoxyglucose-positron emission tomography (FDG-PET)

Background

Microscopically complete (R0) resection of metastases from uveal melanoma prolongs median overall survival compared to incomplete surgery. The aim of this study was to compare the sensitivity of dynamic-enhanced magnetic resonance imaging (MRI) with fluorodeoxyglucose-positron emission tomography (FDG-PET) in the preoperative diagnosis of liver metastases from uveal melanoma.

Patients and methods

Fifteen consecutive patients (mean age: 56 years) underwent FDG-PET and liver MRI. Extrahepatic metastatic disease was excluded by whole body computed tomography and bone scintigraphy. MRI and FDG-PET were performed with a mean of 19 days (range: 1–30) before surgery. Imaging findings were compared with surgical (including intraoperative ultrasonography) and histological findings on a lesion by lesion analysis.

Results

R0 resection was performed in 12 patients. A total of 28 lesions were resected with 27 histologically proven metastases. Nine lesions were smaller than 5 mm, 7 measured 5–10 mm and 11 were larger than 10 mm. Sensitivity and positive predictive value were 67% and 95% for MRI compared to 41% and 100% for FDG-PET. The difference between the two modalities was statistically significant (p = 0.01; McNemar test). In remaining 3 patients, diffuse miliary disease (>10 capsular lesions) was discovered intraoperatively, and was suspected on preoperative MRI in 2 cases. Only one extrahepatic lesion identified by FDG-PET was falsely positive.

Conclusions

In this preliminary study, MRI was superior to FDG-PET for staging of liver metastases from uveal melanoma. Although miliary disease was suggested by MRI in some cases, preoperative confirmation remains imperfect.     

Value of liver scintigraphy in pretreatment staging and in follow-up of patients with malignant melanoma

Liver scintigraphy (99Tcm sulphur colloid) was performed in 118 patients with malignant melanoma. In 73 patients diagnosed as stage I, the pretreatment evaluation showed one false-negative and one false-positive examination. During follow-up there were ten abnormal liver scintigraphies; one was later correlated to liver metastases. In 46 patients diagnosed as stage II-IV, the pretreatment liver scintigraphy yielded false-negative results in 36% and false-positive results in 15%. The predictive values of positive and negative tests were 44% and 81%, respectively. The yields of liver tests (S-alkaline phosphatase, S-gamma-glutamyl-transferase) in patients with liver metastases were low. This study demonstrated the limitations of liver scintigraphy for diagnosis of liver metastases in patients with malignant melanoma.